Hello Greg.
Here is a link to a file with a photo and measurements of an A4 that may be helpful:
https://drive.google.com/file/d/1wBU...ew?usp=sharing
I've marked the known distance from the centers of the mounting holes and extrapolated what the "5.6" appears to refer to. Others who have made this modification hopefully will correct me if I'm wrong.
Best regards,
jack.